It was very strange that my cat, Bear, did not come on our bed during the night, nor early in the morning. He usually does. He didn't even come in the bathroom with me during my shower! I looked all over for him, worried he was sick or something and hiding. Last night, the last I saw him, he was lying by my feet while I watched TV. After checking all his usual places, I opened the den door and out he ran straight for his litter box. It took me a while, but then I realized I came up last night right before bed to close the little window in the bathroom off the den. He must have came up and followed me in there without my noticing. (I always close off the den so our dog doesn't go potty in there which happened a few times.) I was so relieved and happy to see Bear was okay, but felt really bad that he was stuck in the den all night away from us. I pet him up and played with him to make up for it and all is forgiven. He even joined me again in the den this morning!